Most radiotherapists include the lymph node regions when they design
fields to radiate the prostate. Long term results if the nodes are involved is poor
(Hanks) and the RTOG trials showed little or no benefit from including the nodes.

Asbell SO. From 1978 to 1983 the Radiation Therapy Oncology Group conducted a study to
evaluate the role of elective pelvic lymph node irradiation in carcinoma of the prostate.
Eligible patients were those with clinical Stage A2 (occult disease with more than 3
positive chips and poorly differentiated tumor) and Stage B without clinical
(lymphangiogram) or biopsy evidence of lymph node involvement. The patients were
randomized to receive 6.5 weeks of either prostatic bed irradiation only 6500 cGy at
180-200 cGy per treatment or pelvic node irradiation to 4500 cGy with a boost of 2000 cGy
to the prostatic bed bringing the total dose to 6500 cGy. As of February, 1988, the median
follow up has been 7 years and there were 445 analyzable cases who were evaluated for
local control, incidence of distant metastases, ned (no evidence of disease) survival and
survival. The results of the study revealed no statistically
significant benefit of elective pelvic irradiation.

Int J Radiat Oncol Biol Phys 1986 Mar;12(3):345-51

Extended field (periaortic) irradiation in carcinoma of the
prostate--analysis of RTOG 75-06.

Pilepich MV. From 1976 to 1983 the Radiation Therapy Oncology Group conducted a study
of extended field (periaortic) irradiation in carcinoma of the prostate. Eligible patients
were those with clinical Stage C tumor with or without evidence of pelvic lymph node
involvement and also those with Stage A-2 and B with evidence of pelvic lymph node
involvement. The patients were randomized to either receive pelvic irradiation followed by
a boost to the prostate or pelvic and periaortic irradiation followed by a boost to the
prostate. The prescribed daily dose was 180-200 rad to a total midplane dose to the
regional lymphatics to 4000-4500 rad. The prostatic boost target volume was to receive
additional 2000-2500 rad bringing the total dose to that area to a minimum of 6500 rad. No
statistically significant differences between the treatment arms could be documented.
Similarly, no significant difference between treatment arms could be documented within a
number of subpopulations such as those characterized by a particular grade, hormonal
status, stage, age, acid phosphatase level, etc. The results of the study revealed no apparent benefit of elective periaortic irradiation in patients with
detectable disease confined to the pelvis.

Hanks GE. This study was conducted to see what fraction of prostate cancer patients
with biopsy-proven nodes are free of cancer 10 years after radiation treatment. METHODS
AND MATERIALS: RTOG protocol #75-06 included 90 patients with biopsy-proven pelvic nodal
involvement treated with radiation. They have been continuously follow-up since treatment.
When feasible, current prostate-specific antigen (PSA) levels have been solicited from
patients clinically cancer-free (no evidence of disease, NED) at 10 years, to confirm
cure. RESULTS: The 10-year survival was 29%, the 10-year
clinical NED survival 7%.

NCI Monogr 1988;(7):61-5

Radiation Therapy Oncology Group studies in carcinoma of the
prostate.

Pilepich MV. From 1976 to 1983, the Radiation Therapy Oncology Group (RTOG) conducted 2
large-scale phase III trials of extended field irradiation in patients with carcinoma of
the prostate. The first, RTOG 75-06, was designed to test the value of elective periaortic
irradiation in patients in whom the tumor extended beyond the gland, but remained limited
to the pelvis, and the second, RTOG 77-06, was designed to test the value of elective
pelvic irradiation in patients without evidence of spread beyond the prostate. The results indicated no apparent benefit from elective periaortic
irradiation in patients with detectable disease confined to the pelvis and no apparent
benefit from elective pelvic irradiation in patients with detectable disease confined to
the prostate. Patients with extracapsular extension of the primary tumor and
evidence of pelvic lymph node involvement demonstrated an outcome comparable to that in
patients without evidence of lymphatic involvement. This observation may reflect a
beneficial effect of pelvic irradiation in patients with nodal involvement. In
contradistinction to elective irradiation of regional lymphatics, therapeutic irradiation
(of the involved lymphatics) may prove strongly indicated. A prospective study testing
this contention needs to be conducted.

Oncology (Huntingt) 1998 Oct;12(10):1467-72; discussion 1472, 1475-6

Does pelvic irradiation play a role in the management of
prostate cancer?

Stock. Studies of prostate irradiation with and without inclusion of the pelvic lymph
nodes show poor outcomes for node-positive patients, supporting the concept that many of
these patients have systemic disease at presentation. Although no randomized trial has
examined the role of pelvic irradiation in pathologically node-positive patients,
available data fail to reveal any significant benefit of this approach over prostate-alone
irradiation. More promising therapeutic approaches involve the combination of local
therapy and sustained hormonal therapy. Series comparing prophylactic irradiation of the
pelvis and prostate to irradiation of the prostate alone have shown no clear benefit of
pelvic irradiation. Pelvic irradiation may play a role in the treatment of early-stage or
occult nodal disease, although this has yet to be examined.

Strahlenther Onkol 1998 May;174(5):231-6

Locally advanced prostate carcinoma (T2b-T4 N0) without and with
clinical evidence of local progression (Tx N+) with lymphatic metastasis. Is radiotherapy
for pelvic lymphatic metastasis indicated or not?

Wiegel . There is a greater controversy regarding the indication of radiotherapy of the
pelvic lymphatics in patients with suspected lymph node metastases in locally advanced
prostate cancer (T2b-4 N0) on the one hand and in patients with pathologically proven
lymph node metastases in locoregional advanced prostate cancer (Tx pN+) on the other hand
following definitive radiotherapy and radical prostatectomy. the RTOG conducted 2
prospective randomised studies (RTOG 75-06, 77-06) to address these questions. However,
the results of these studies showed no better survival or cause specific survival for
patients treated for the paraaortal or pelvic lymphatics and therefore, radiotherapy of
the pelvic lymphatics was no more advocated. A reanalysis showed several problems of the
study design and it was concluded that the studies couldn't prove the question of elective
radiotherapy of the pelvic lymphatics. Today there is no indication for treating the
paraaortal lymphatics in patients with locoregional advanced prostate cancer. Many
radiotherapists perform the elective radiotherapy of pelvic lymphatics when the risk of
metastases is above 15 to 20% because retrospective data indicate a better outcome. On the
other hand, many others don't treat them because RTOG 75-06 and 77-06 didn't demonstrate a
better outcome. In case of radiotherapy of the pelvic lymphatics a dose of 45 Gy for
suspected metastases and 50.4 Gy for proven metastases is recommended